Methods and apparatus for inhibiting infection of subcutaneously implanted devices

ABSTRACT

Implantable ports and other devices are cleansed by the injection of a washing solution into a region in the device or in a tissue pocket surrounding the device. In a first embodiment, the washing solution is injected through an aperture in the device to flush internal regions of the device before infusing the tissue pocket and flushing outwardly through a tissue tract leading to the device. In other embodiments, the washing solution is injected directly to a target site on the exterior of the device. Implantable devices may include special, usually hardened, target regions for receiving the sharpened end of a needle used to inject the washing solution. Kits will include devices, syringes, access devices, and instructions for cleansing according to the methods of the present invention.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation-in-part of pending application No.09/161,044, filed on Sep. 25, 1998, which was a continuation-in-part ofpending application No. 09/003,772, filed on Jan. 7, 1998, the fulldisclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to medical devices and methods.More particularly, the present invention relates to methods forinhibiting and treating the infection of implanted devices and tomodified devices which facilitate such methods.

Subcutaneously and transcutaneously implanted devices are utilized for awide variety of purposes. Heart pacemakers have become commonplace.Transvascular catheters are used for a variety of purposes, includinghemodialysis access, drug infusion, and the like. Of particular interestto the present invention, subcutaneously and transcutaneously implantedports and catheters have been proposed for both drug infusion andhemodialysis access. All such implanted devices are subject toinfection. Subcutaneously implanted ports which are periodicallyaccessed by needles and other percutaneously introduced devices areparticularly subject to infections introduced by the access device.

Most infections of subcutaneously implanted ports begin as bacteria fromthe skin are carried into the tissue tract and port by the needlepenetration. An infection can then grow internal to the port or withinthe tissue “pocket” which surrounds the port. A tissue pocket will formwhen the exterior surface of the port or other device is impermeable totissue in-growth, e.g. where the surface is hard and composed of ametal, such as stainless steel, titanium, plastic, or the like.Infection can enter the space between the external surface of the deviceand the opposed tissue surface and can spread throughout the tissuepocket and sometimes into adjacent spaces, e.g. the space around acannula attached to the port and leading to a blood vessel or other bodylumen. While initially localized, the infection can become systemic andplace the patient at significant risk.

Heretofore, infections of subcutaneously implanted devices have usuallybeen treated by the systemic administration of antibiotics to thepatient after infection has become established. Often, the implanteddevice must also be removed and replaced, subjecting the patient toadditional trauma and leaving the patient without benefit of the devicefor the time it takes to clear the infection and replace the device.Moreover, the need to administer antibiotics periodically to patients isexpensive and patients who suffer from repeated infections often becomeresistant to particular antibiotics.

As an alternative to antibiotic treatment and/or device removal, U.S.Pat. No. 5,263,930 proposes to provide a disinfectant reservoir in animplantable vascular access port. The reservoir includes a septum topermit periodic replenishment with a suitable anti-microbial agent.Agent introduced into the reservoir flows into an access lumen throughthe device. Catheters and other devices inserted into the access lumenbecome coated with the anti-microbial agent to provide a barrier againstinfection along the percutaneous access route. In particular, the designis intended to prevent infection of the bloodstream. While potentiallybeneficial, the provision of a static volume of anti-microbial agentwithin a reservoir does not provide flushing and active decontaminationof the tissue pocket surrounding the implanted port. Thus, shouldbacteria be introduced into the tissue pocket, it is unlikely that theanti-microbial agent would be effective to inhibit infection.

In addition to the procedural shortcomings described above, conventionaltreatments with antibiotics and other anti-microbial agents areundesirable because of the nature of the antibiotic and anti-microbialagents themselves. Many patients are allergic to antibiotics and otheranti-microbial agents. Additionally, the repeated use of antibiotics totreat recurrent infections (of the type which would often be associatedwith implanted devices) can often lead to antibiotic resistance which,over time, can render further antibiotic treatments ineffective.

For these reasons, it would be desirable to provide improved methods anddevices for inhibiting bacterial and other infections in subcutaneouslyimplanted devices. It would be particularly desirable to provide methodsand devices for active flushing of the implanted device as well as thetissue pockets and regions surrounding the device in order to maximizethe disinfection process. It would be particularly useful if suchmethods and devices could use washing solutions which are free fromantibiotics and/or other biologically active agents intended for killingthe bacteria associated with an infection. It would be still firtherdesirable if such methods and devices were applicable not only toimplantable ports but also to other subcutaneously and transcutaneouslyimplanted devices. At least some of these objectives will be met by thepresent invention as described hereinafter.

2. Description of the Background Art

U.S. Pat. No. 5,263,930 has been described above. A transcutaneousvascular access port sold under the tradename HEMASITE® II by RenalSystems, Inc., Minneapolis, Minn., includes an above-skin reservoir fora bactericide, as described in a brochure entitled Vascular AccessSystem copyrighted by the manufacturer in 1984. Catheters havingbactericidal coatings and release capabilities are described in U.S.Pat. Nos. 5,599,321; 5,591,145; 5,482,740; 5,261,896; 5,236,422;5,004,455; 4,959,054; 4,767,41 1; and 4,579,554.

SUMMARY OF THE INVENTION

The present invention provides methods and improved apparatus systems,and kits for inhibiting and/or treating infection of subcutaneously andtranscutaneously implanted devices. As used hereinafter, the phrase“inhibiting infection” will refer to both prophylactic treatment toavoid infection and therapeutic treatment to eliminate an establishedinfection. The methods and apparatus are particularly applicable totreatment of implanted vascular and other access ports which are atsubstantial risk of infection through repeated percutaneous access vianeedles, access cannulas, stylets, and the like. The present invention,however, will also be useful with a variety of other subcutaneouslyimplanted devices, including pacemakers, catheters, prosthetic joints,defibrillators, implantable infusion pumps, and the like.

The present invention relies on percutaneous injection of a washingsolution in an amount sufficient to flush a region within and/orsurrounding the device. For prophylactic treatment, the washing solutionmay be any one of a variety of conventional washing solutions used forirrigation, lavage, and the like. Suitable washing solutions includesaline, normal saline, and the like. While these solutions may includebuffers, preservatives, and other conventional additives for washingsolutions, they will generally be free from antibiotics andanti-microbial agents at a level which would have a microbicidal effectwhen administered to subcutaneous device sites according to the methodsof the present invention.

For treatment of established infection, the washing solution willusually be the same, although in some cases the treatment may besupplemented with the systemic administration of an antibiotic, such aspenicillin, vancomycin, and the like. The washing solution will beflowable so that it can be percutaneously introduced to the implanteddevice, usually being in the form of a liquid, although it could also bea flowable gel, and will usually be injected at a volume in the rangefrom about 0.5 ml to 1000 ml, often from 1.0 ml to 500 ml, more oftenfrom 2.0 ml to 100 and typically from 5.0 ml to 50 ml. Injection willconveniently be effected using a needle which can be penetrated directlythrough the skin, typically in combination with a conventional syringe.

The ability of the present invention to inhibit infection, eitherprophylactically or in the case of established infections, depends onthe ability to flush the subcutaneously implanted device as well as thesurrounding tissue, tissue pocket, and other sites where bacteria mayaccumulate and proliferate. Thus, it will generally be preferred tointroduce volumes of the washing solution which are in substantialexcess over the available void volume in the device in the surroundingtissue pocket. For most devices, it will be desirable to introduce avolume of the washing solution which is at least twice that of thecombined void volume and internal volume of the tissue pocket,preferably being at least three times such volumes, more preferablybeing at least five times such volumes, and sometimes being at least tentimes such volumes, or greater. Thus, the volume of washing solutionintroduced will depend to a great extent on the size of the implanteddevice and tissue pocket surrounding the device. Usually, volumes ofwashing solution as set forth above will be sufficient.

The extent and nature of the region which is flushed will depend greatlyon the geometry and type of the implanted device. For implanted deviceshaving internal spaces, such as implanted ports having apertures forreceiving percutaneous access tubes, it will usually be desirable toflush at least the internal space with the washing solution. Preferably,at least a portion of any tissue pocket surrounding the implanted devicewill also be flushed with the washing solution. More preferably, asufficient amount of the washing solution will be introduced to flushoutwardly through the access tissue tract which is used to introduce theflushing needle and/or to subsequently introduce an access tube. Inparticular, the present invention is able to cleanse the tissue tractused for subsequently introducing an access tube.

For transcutaneously implanted device, i.e. devices which pass throughan access site in the patient's skin (such as transcutaneous catheters),the washing solution is preferably introduced at a site just proximal toan infection barrier, such as an infection-inhibiting cuff on thecatheter. In this way, the washing solution can be flushed outwardlyback through the tissue track surrounding the catheter or other deviceand through the access site in the skin. The ability to flush thebacteria from the tissue region surrounding the transcutaneous catheteror other transcutaneous device is particularly beneficial in inhibitinginfection.

In a preferred aspect of the method of the present invention, thesubcutaneously implanted device is a port which is connected to a bloodvessel, other body lumen or cavity, or solid tissue target site, usuallyusing a cannula. The port has an aperture for receiving a percutaneousaccess tube, e.g. a needle. The washing solution is injected directlyinto the aperture to flush both the aperture and any internal volumesurrounding or in fluid communication with the aperture, with excesswashing solution being flushed from the aperture to infuse a region orspace surrounding the port within the tissue pocket in which the porthas been implanted. Usually, the port will be valved or have a septum toisolate the access aperture from that portion of the port which isconnected to the cannula and/or the blood vessel or body lumen. Thus,flushing of the port with the washing solution can be performed withoutintroduction of the solution beyond the valve, i.e. into the bloodvessel or other target site. The needle used to flush the access portwill be introduced in a manner which does not open the valve structureor septum, thus maintaining isolation. The needle used to introduced thewashing solution, however, will usually be introduced through the samesite or tissue tract as the primary access tube, thus reducing patienttrauma. The washing needle will usually be smaller than the access tube,even further reducing patient trauma.

The methods of the present invention are also useful for flushing andinhibiting infection with ports and other subcutaneously implanteddevices which do not have open access apertures. In such cases, it willusually be unnecessary to flush internal portions of the device, and thewashing needle can be contacted directly against an external surface ofthe device in order to infuse the washing solution within the tissuepocket surrounding the device. Optionally, the needle may be contactedagainst a specially configured target site on the device, e.g. a well orother region on the device composed of or lined with a relatively hardmaterial that can withstand repeated contact with the washing needle.The well or other target can be located by the treating professional,e.g. by manually feeling it through the skin, and will be positioned topermit the washing solution to flush freely about the exterior of thedevice at the interface between the device and the tissue. In somecases, it may be desirable to connect the well to channels or othersurface features which permit the washing solution to suffuse freelyaround the periphery of the device.

In yet another embodiment, the methods may be used to washtranscutaneously implanted devices, such as catheters. In such cases,the washing solution is infused into the tissue pocket formed about thedevice, usually by injection into tissue through a location adjacent todevice penetration site. As with previous embodiments, the washingsolution is able to suffuse and flush the tissue pocket, and the excesswashing solution will flow outward around the device onto the patient'sskin, to assure thorough cleansing.

In an alternative aspect, a method according to the present inventionfor detecting infection of an implanted device comprises injecting awashing solution through a tissue tract into a region within orsurrounding at least a portion of the device. The washing solution willusually be saline, water, or other sterile material which can flow intothe region, flush the region, and carry visible products of infectionback outwardly through the tissue tract. At least a portion of theinjected material will flow outwardly back through the tissue tract inorder to transport visible material resulting from infection back to thesurface of the skin. By then observing that portion of the injectedmaterial which flows outwardly from the tissue tract, a determinationcan be whether an infection exists. Usually, the material which isinitially injected will be relatively clear. If the material which isflushed from the tissue tract is milky and contains considerable debris,it is likely that an infection has become established. In that case, theinfection may be treated by irrigating the device with a large volume ofa washing solution according to the present invention. Alternatively oradditionally, the patient could be treated with systemic antibiotics orin other conventional ways.

The present invention still further provides systems for cleansing andaccessing an implanted port. The systems will comprise a needle adaptedto deliver a washing solution to the implanted port, typically accordingto the methods described above. Usually, the needle will be attached toa syringe, and the syringe will usually be pre-filled with a suitablewashing solution. The types and amounts of washing solution will begenerally as described above. The system will still further include anaccess tube suitable for percutaneously coupling to the implanted portto deliver or receive a flowable material therefrom, e.g. in the case ofports connected to the vasculature. In other instances, the washingsolution may be dialysate used in peritoneal dialysis. The access tubemay also be in the form of a needle, and will usually be connected to acatheter having a hub or other structure at its proximal end forconnecting to external equipment. Such systems may further compriseinstructions for delivering the washing solution to the implanted devicethrough the needle and thereafter for connecting the access tube to theimplanted port after it has been cleansed. Optionally, the systems maybe packaged together in conventional packages, such as pouches, trays,tubes, boxes or the like.

The present invention still further comprises kits including one or moreof the apparatus and system components described above together withinstructions for use according to any of the methods described above.For example, a kit according to the present invention may comprise anyimplantable device, such as an implantable port intended forpercutaneous access via an access tube as described above, together withinstructions for use for inhibiting infection of the device byintroducing a washing solution to the device after it has beenimplanted. A second exemplary kit might comprise a container holding avolume of the washing solution, e.g. a syringe holding the washingsolution having a needle for introducing the solution through thepercutaneous tissue tract. The container or syringe would be combined ina kit with instructions for use setting forth methods for introducingthe washing solution from the container through a tissue tract orinjection site to an implanted device. A third exemplary kit wouldinclude the container and instructions for use, as just described,further in combination with an access tube intended for accessing animplantable port. A fourth exemplary kit would include the access tubetogether with instructions for use for introducing a washing solutionthrough a tissue tract prior to introducing the access tube through thesame tissue tract. All of the above kits will typically be placedtogether in a common package, such as a pouch, box, tube, tray, or thelike. More usually, all kit components will be sterilized within thepackaging and will be available for immediate use after the package isopened.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates an implanted vascular port having an access aperturebeing cleansed according to the method of the present invention.

FIG. 1B illustrates the implanted vascular port of FIG. 1A having anaccess tube introduced through the tissue tract after the device, tissuepocket, and access tissue tract have been cleansed.

FIG. 2 is a detailed view of the port of FIG. 1, with portions brokenaway, illustrating the flow of washing solution within the internalregions of the port.

FIG. 3 illustrates an implanted port which has been modified tofacilitate cleansing according to the methods of the present invention.

FIG. 4 illustrates a port of FIG. 3 undergoing such cleansing.

FIG. 5 illustrates an alternative embodiment of an implantable portwhich has been modified according to the present invention.

FIG. 6 illustrates a transcutaneously implanted catheter undergoingcleansing according to the method of the present invention.

FIG. 7 illustrates a transcutaneously implanted catheter which has beenmodified to facilitate cleansing according to the methods of the presentinvention.

FIG. 8 illustrates a kit according to the present invention comprisingan implantable port, instructions for use, and a package.

FIG. 9 illustrates a second kit according to the present inventioncomprising a syringe pre-loaded with a washing solution, an access tubeattached to a catheter, instructions for use, and a package.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

The present invention provides novel methods for cleansingsubcutaneously and transcutaneously implanted devices subject to suchinfection. The methods rely on injecting a suitable washing solutioninto a region or regions within a subcutaneous pocket into which thedevice has been previously implanted. Optionally, the washing solutionwill be injected through an aperture in order to flush internal spaceswithin the device, where excess washing solution will then suffuseoutwardly through the same aperture and infuse into the tissue pocket.Alternatively, the washing solution may be injected directly onto atarget site on the exterior of the device. In both cases, it will begreatly preferred to introduce a sufficient volume of the washingsolution so that the solution will flush the tissue pocket as well asany open internal spaces within the device, and the spent washingsolution will then flow outwardly through the tissue tract to carrybacteria and other contaminating substances away from the implantationsite. Thus, it will be preferred to introduce the washing solution inlarge excess volume so that the tissue pocket and any open volume of thedevice will be substantially completely flushed and most or all of thecontaminating materials be carried away. Flushing need only reduce thebacterial load sufficiently to enable the patient's immune system tosuppress the remaining bacteria.

The washing solution is usually in a liquid form, e.g., such as saline,sterile water, Ringer's solution, or the like. Alternatively, thewashing solution may be in the form of a gel, emulsion, suspension,paste, powder, or other injectable fluid or material of a type normallyemployed in pharmaceutical uses.

The washing solution will be injected in an amount sufficient to flushat least a portion of the region surrounding the subcutaneously ortranscutaneously implanted device, referred to herein as the “tissuepocket.” Usually, the volume of washing solution injected will besufficient to flush through the entire tissue pockets surrounding devicepreferably at least several times. When injected only on the exterior,the volume will usually be at the lower end of the ranges set forthabove, e.g. from 0.5 ml to 10 ml. Often, however, in cases whereinternal portions of the device are also being flushed, the volume willusually be greater, i.e. being sufficient to completely fill and flushthe internal regions as well as having sufficient excess to infusethrough at least a portion, and preferably all, of the tissue pocket.Preferably, the volume will be sufficient to further express outwardlyfrom the tissue pocket through the needle puncture site to flushpotentially infecting organisms away from the implanted device andtissue tract. Such volumes will be in the range from 0.5 ml to 50 ml. Inthe case of implanted access ports, the volume will typically be in therange from 0.5 ml to 25 ml, more usually from 1 ml to 10 ml.

When cleansing an implanted port having a predefined tissue tractleading to the port, as generally described in co-pending applicationNos. 08/896,592 and 08/071,241, it will usually be desirable to flushthe tissue tract as well as the device and tissue pocket or other spacesurrounding the device prior to and/or after the device being accessed.As the pre-existing tissue tract will be used to subsequently introducean access device, e.g. a large bore needle, it will be desirable toleave a portion of the washing solution within the tissue tract tocleanse the site and carry away bacteria that may be present on theaccess device as it is introduced. As will be described in more detailhereinafter. Introduction of the washing solution using a needle placedthrough the pre-existing tissue tract will normally result in a portionof the washing solution being flushed out through the tissue tract toprovide the desired cleansing.

Referring to FIGS. 1A, 1B and 2, a first exemplary method according tothe present invention will be described. A subcutaneously implanted port10 is of the type which includes an aperture 12 for receiving apercutaneously introduced access tube (not shown), of the type describedin co-pending application Ser. No. 08/857,386, filed on May 15, 1997,assigned to the assignee of the present invention, the full disclosureof which is incorporated herein by reference. In normal use, the accesstube is introduced through the aperture 12 and a fluid is transferredbetween the access tube and an implanted cannula 14, which may beconnected to a blood vessel, the peritoneal cavity, or other target sitewithin the patient. The port 10 further comprises a valve structure 18,where the valve is normally closed, i.e. closed in the absence of theaccess tube. For the purposes of the present invention, the details ofthe valve mechanism 18 are unimportant. It is important only that thevalve is actuated when a relatively large access tube is introducedthrough the aperture 12, e.g. a fourteen gauge access tube in the caseof the specific port 10 described in the co-pending application.

Cleansing of the port 10 is accomplished using a needle 20 which issmaller than the access tube which is normally used to access the port.For example, a twenty-five gauge needle 20 may be introduced through theaperture 12 and substantially to the bottom of a vertical access path22, as best seen in FIG. 2. The needle encounters a metal surface at thebottom of the access path 22, so the valve structure 18 is not damaged.Introduction of the smaller needle 20 does not actuate the valvemechanism, so the valve 18 remains closed, isolating the aperture 12 andaccess path 22 from the cannula 14.

After the needle 20 is in place, as shown in FIGS. 1A and 2, the washingsolution may be injected using a syringe assembly 30 connected to theneedle 20, in a conventional manner. Valve ports 10 of the typedescribed in the co-pending application, a volume of washing solution inthe range from 3 ml to 10 ml has been found to be sufficient to bothirrigate and flush the access path 22 and associated interior volumes ofthe port as well as flush about the exterior of the port, as shown bythe arrows in FIG. 1A. The injection of washing solution may beperformed before access with an access tube, after access with an accesstube, or at any other time. A particular advantage of the methodillustrated in FIGS. 1A and 2 lies in the fact that no additional tissueaccess tract needs to be formed in order to introduce the washingsolution. That is, the needle 20 may be introduced through the normaltissue tract which is formed in order to access the port with the accesstube.

After the needle 20 is removed from the tissue tract, an access tube 100may be introduced through the tissue tract to the port 10, asillustrated in FIG. 1B. The access tube 100 will typically be connectedto a catheter 102 which may be connected to any external device orsource needed for performing a procedure, e.g. a hemodialysis machine, adialysate source for performing peritoneal dialysis, or the like.

The cleansing methods of the present invention are also useful with awide variety of other implanted devices. For example, as illustrated inFIGS. 3 and 4, a septumtype port 50 may be washed by engaging a needle52 against an exterior surface of the device, and injecting a suitablewashing solution using a syringe 54. Optionally, the port 50 may bemodified to have a target site or region 54, which is shown to be in theform of an annular trough formed concentrically about the septum 56. Itwill be appreciated that many implantable devices have smooth surfacewhich are difficult to contact with a needle and/or silicone rubber orother penetrable surfaces which will be penetrated by any needle used tointroduce a washing solution. By providing a nonpenetrable target site,usually being formed of a material which is harder than the needle to beused, engagement of a needle against the device can be facilitated.Trough structures, such as trough 54, also serve to distribute thewashing solution about at least a portion of the exterior of the deviceto facilitate and enhance infusion of the washing solution over allportions of the surrounding tissue pocket.

An alternative septum-type port 70 having a circular needle target site72 is illustrated in FIG. 5. In that embodiment, the target is a simpleconical indentation in the metallic body of the port 70. The target site72 is laterally spaced-apart from the septum 74. The treatingprofessional can manually locate a target site 72 and percutaneouslyaccess the target site using a needle to introduce the washing solutionin a straightforward manner.

The methods of the present invention are also suitable for cleansingtranscutaneously implanted devices, such as transcutaneous catheter 80,as illustrated in FIG. 6. Transcutaneous catheters are provided for avariety of purposes, including hemodialysis and peritoneal dialysisaccess. A free, proximal end of the catheters generally remainsaccessible above a patient's skin, while a cuff 82 acts as an infectionbarrier below the skin. While the cuff 82 is generally effective toprevent the progress of an infection down the catheter, there is still aregion between the cuff and the skin surface which is subject toinfection. The present invention can be used to flush that area with awashing solution using a needle 84 and syringe 86, as shown in FIG. 6.The needle 84 is introduced through the percutaneous tissue opening, andthe needle tip inserted along the tunnel/tract surrounding the catheter.The syringe 86 is then used to inject the washing solution into thetissue pocket until it encounters the implanted cuff 82. Preferably, theneedle 84 will be blunt at its tip in order to avoid damage to thecatheter. Alternatively, the catheter could be clad with a protectivesheath for use with a sharp needle. The washing solution will thusgenerally fill and flush the tissue pocket and eventually pass outwardlythrough the region surrounding the transcutaneous penetration on thepatient's skin surface.

Transcutaneous catheters of the type illustrated in FIG. 6 may beimproved by providing a hardened target region 90, preferably at alocation immediately proximal of the implantable cuff 82, as shown inFIG. 7. The target region may be in the form of a metal sleeve having aconical or other depression designed for receiving the sharpened distalend of needle 84. The needle 84 may then be percutaneously introducedthrough the skin so that its distal tip engages the target region 90.The washing solution may then be injected from the region immediatelyadjacent the implanted cuff 82 so that the washing solution flowsgenerally outwardly, as illustrated by the arrows of FIG. 7. Suchone-way flushing may in some instances provide a more effectivecleansing action.

Referring now to FIG. 8, an implantable device 200, illustrated as animplantable port, may be packaged together with instructions for use(IFU) in a kit. The implantable device will typically be packaged in apouch, tube, tray, box, or the like, or any other type of container 202.The IFU's may be printed on a separate sheet of paper 204 and/or may beprinted on the packaging material itself. Optionally, but notnecessarily, the implantable device may be sterilized within thepackage, e.g. by radiation or by exposure to ethylene oxide or steam.The instructions on the IFU may set forth any of the aspects of themethods of the present invention described above.

FIG. 9 illustrates a kit similar to that shown in FIG. 8, except thatthe kit may comprise a needle and syringe assembly 210, where thesyringe is pre-loaded with a washing solution useful in the methods ofthe present invention. Additionally or alternatively, the kit maycomprise an access tube, generally as described in the prior patentapplication as referenced herein above. The kit will further compriseinstructions for use setting forth any of the aspects of the presentinvention. All or any of the components will be placed together in acommon package 220, which may take any of the forms described above.

While the above is a complete description of the preferred embodimentsof the invention, various alternatives, modifications, and equivalentsmay be used. Therefore, the above description should not be taken aslimiting the scope of the invention which is defined by the appendedclaims.

What is claimed is:
 1. A method for inhibiting infection of an implanteddevice, said method comprising percutaneously injecting or withdrawing afluid through a single percutaneous access tract to the device; and;injecting a washing solution through the same percutaneous access tractto the device in an amount sufficient to flush a region within orsurrounding the device such that the washing solution flows outwardlyback through the access tract.
 2. A method as in claim 1, wherein thewashing solution is selected from the group consisting of saline,sterile water, and Ringer's solution.
 3. A method as in claim 1, whereinthe washing solution is injected at a volume in the range from 0.5 ml to1000 ml.
 4. A method as in claim 1, wherein the washing solution isinjected from a syringe through a needle which is percutaneouslyintroduced to the device.
 5. A method as in claim 1, wherein the deviceis selected from the group consisting of ports, catheters, andpacemakers.
 6. A method as in claim 5, wherein the device is asubcutaneously implanted port having a cannula connected to a bloodvessel or other body lumen or cavity.
 7. A method as in claim 1, whereinthe washing solution is injected against an external surface of thedevice.
 8. A method as in claim 7, wherein the washing solution isinjected via a needle which is contacted against a target site on theexternal surface of the device, wherein the target site is harder than adistal tip of the needle.
 9. A method as in claim 1, wherein the washingsolution is injected into an internal volume within the device andinfuses outwardly from the volume to the region surrounding the device.10. A method for inhibiting infection of an implanted port which has anaperture for receiving an access tube, said method comprisingsubcutaneously injecting a washing solution through a tissue tract intothe aperture in an amount sufficient to at least partly fill saidaperture and to overflow from said aperture to infuse a regionsurrounding the port within a pocket of tissue and to flow outwardlyback through the access tract.
 11. A method as in claim 10, wherein thewashing solution is selected from the group consisting of saline,sterile water, and Ringer's solution.
 12. A method as in claim 10,wherein the washing solution is a liquid injected at a volume in therange from 0.5 ml to 1000 ml.
 13. A method as in claim 10, wherein thewashing solution is injected with a syringe through a needle which ispassed through the aperture.
 14. A method as in claim 10, wherein theaperture is sized to mate with a access tube having a preselected sizeand wherein the washing solution is injected with a needle having a sizesmaller than the preselected size so that the washing solution mayinfuse outwardly through the aperture past the needle.
 15. A method asin claim 14, further comprising introducing or withdrawing a fluidthrough an access tube percutaneously positioned in the aperture.
 16. Amethod as in claim 15, wherein the washing solution is injected beforethe fluid is withdrawn or introduced.
 17. A method as in claim 15,wherein the washing solution is injected after the fluid is withdrawn orintroduced.